Exam 1 - 8. Projection Geometry Flashcards
2
____ measures how well a boundary betwen two areas of a differing radiodensity is revealed.
3
____ measures how well a radiographic is able to reveal small objejcts that are close together.
4
Since x-rays are ____ in nature, their projection of an object do not ____ at the _____ on an image receptor. Therefore, there is a zone of ______ known as the _____.
5
The focal spot size should be ______
6
What is the term for the region on the target which represents the total area of the target where electrons are focused on.?
6
What is the term for the area measured under the anode and is a function of the angle of the target?
6
When the angle of the target with respect to the central X-ray beam is small, so is the _____. This ____ sharpness.
7
Increasing the source-to-object distance reduces the _____ of the x-ray beam.
9
Image distortion is when an image appears smaller or larger than the original object. This occurs when not all parts of the object are at the ______.
10
When does foreshortening occur?
11
When does elongation occur?
12
What are the two ways to minimize shape discrepancies with x-rays?
15
What are two methods for obtaining the third dimensional view?
17
What is the SLOB rule?
19
The SLOB rule may be used to locate the ____ or ____ position of the object as well.
20
What is the Egg Shell Effect?
21
What are the three categories of intraoral radiographs?
21
What do periapical projections show?
21
What do bitewing projections show?
21
What doe occlusal projections show?
22
What are the two techniques for intraoral X-ray acquisition?
22
Paralleling (long cone) technique requires at least ____ (size of long cone).
24
What is the bisecting angle technique?
25
What is the preferred technique for periapical radiography?
26
Use of bisecting angle technique may be needed in special situations such as _____. But, routine use is not recommended.
29
For PAs, the ____ of the crown and root should be visible.
29
In PAs, at least ____,, of apical bone should be visible past the apex.
40
____ is the movement of an x-ray cone nad beams in an up and down direction.
40
With vertical angle, heam hits the tooth and receptor at a ____.
44
___ is movement of x-ray cone and beam side to side.
44
With the horizontal angle, the beam is directed through the _____ to open contacts.
50
What are 5 reasons for taking bitewing radiographs?
51
What are the two most cirtical requirements for bitewing radiographs?
71
For occlusal radiograhy, a size ___ PSP is used.
71
Occlusal radiography shows a ____ than periapical.
72
Occlusal radiographs localize objects in ____ like an impacted teeth,
72
Occlusal radiographs can be used to evaluate the _____ in the jaw and the ____ of the jaw.
72
Occlusal radiographs can detect ____ in the submandibular gland.
72
Occlusal radiographs can be used for patients who cannot ____ or for children who are too small for PA radiographs.
84
Always ____ to make sure that the sensor is centered in the right position.
